RT-A corresponds to the catalytic A chain encoded by the Ricinus communis ricin toxin (RT) gene (UniProtKB:P02879). RT-A can be used as a cell ablation tool; it inhibits eukaryotic protein synthesis via hydrolysis of a specific N-glycosidic bond in 28S rRNA, inactivating the ribosome (PMID:3288622). By expressing RT-A without the B chain that is normally also encoded by the Ricinus communis RT gene (PMID:2999712), the cell ablation caused by RT-A is expected to be cell autonomous.